Hello Mike,
My guess is that there is some file/folder within the last sample set that you installed that had a non 7-bit character in a file/folder name, or had some unexpected file permissions, preventing the file/folder from being deleted on macOS. Try rebooting, then (before launching Hauptwerk), use Finder to delete all files/folders within the following folder manually and completely (but not the folder itself):
/Users/mikeedington/Hauptwerk/HauptwerkSampleSetsAndComponents/TemporaryFiles
... then empty macOS' 'trash can' for good measure.
[In order to be see your OS account's home folder, make sure that the 'Sidebar | Devices | <your-os-account-name>' option is ticked in Finder's preferences.]